Long-wavelength semiconductor substrate and laser chip

The utility model provides a long-wavelength semiconductor substrate and a long-wavelength semiconductor laser chip prepared from the long-wavelength semiconductor substrate. Wherein the long-wavelength semiconductor substrate comprises a substrate and a gain region growing on the substrate; wherein the gain region comprises at least three InGaAsP gain layers, each InGaAsP gain layer comprises an upper waveguide layer, two layers of strained quantum wells, a quantum barrier and a lower waveguide layer, and every two adjacent InGaAsP gain layers are separated by an InP spacing layer. The long-wavelength semiconductor substrate and the long-wavelength semiconductor laser chip prepared from the long-wavelength semiconductor substrate can regulate and control a light-emitting mode field, and realize a low divergence angle and high single-mode fiber coupling efficiency of the chip, thereby improving the light-emitting power of the long-wavelength semiconductor laser chip. 本申请提出了一种长波长半导体基片以及由该长波长半导体基片制得的长波长半导体激光器芯片